The dashboard error is occurring intermittently.

User_P0XGZ

OBIEE 12C Analysis/Dashboard is giving below error:

State: HY000. Code: 59001. [nQSError: 59001] Join operation is not permitted on operand(s). (HY000)
State: HY000. Code: 46035. [nQSError: 46035] Datatype(CHAR) nullable(0) unicode(1) external char(0) conversion to datatype(INTEGER) nullable(0) unicode(1) external char(0) is not supported. (HY000)

The solution offered in oracle doc: Document 2817949.1 is also not helpful. We are getting error while intermittently the dashboard/analysis is working fine.
Below is the solution offered by oracle which is not working in this scenario.

Update the prefix of the affected analysis, but adding the following code in the Prefix section in the Advanced tab:
set variable OBIS_USE_EAGER_JOIN=0

Can I get help on resolving this?